Sand blowing machine



y 7, 1957 J). N. DEMMLER 2,791,013 4 SAND BLOWING MACHINE Filed Feb. 23, 1954 4 Sheets-Sheet 1 J. N. DEMMLER 2,791,013

SAND BLOWING MACHINE May 7, 1957 Filed Feb. 23, 1954 4 Sheets-Sheet 2 Inventor JOHN N. DEMMLER y 7,1957 J. N. DEMMLER 2,791,013

4 SAND BLOWING MACHINE Filed Feb. 25, 1954 4 Sheets-Shed :s

2 In ventor JOHN N. DEMMLER 3 I @Ao-W May 7, 1957 J. N. DEMMLER SAND BLOWING MACHINE 4 Sheets-Sheet 4 Filed Feb. 25. 1954 Inventor JOHN N. DEMMLER Pi; b @Aawrv l ln ited States Patent SAND BLOWING MACHINE John N. Demmler, Kewanee, Ill.

Application February 23, 1954, Serial No. 411,811

3 Claims. (Cl. 22-36) My invention relates to sand blowing machines and is more particularly concerned with machines for blowing sand into molds, core boxes and similar enclosures.

An object of my invention is to provide sand blowing machines with mechanism whereby the sand blown into the molds, core boxes, or similar enclosures can be subjected to a mechanical squeeze to compact the sand more firmly.

Another object of my invention is to provide sand blowing machines in which this squeeze can be efiected automatically as one step in the sequence of operating steps of the machine.

Another object of my invention is to provide a sand blowing machine in which the mechanical squeeze on the sand can be .applied throughout the total area or limited to particular areas as desired.

Another object of my invention is to provide new and improved mechanism for effecting this mechanical squeeze.

Other objects and advantages will become apparent as the description proceeds.

In the drawings:

Fig. 1 is a partial vertical sectional view of a sand blowing machine embodying one form of my invention;

Fig- 2 is a view similar to Fig. 1 but showing a second form of my invention;

Fig. 3 is a view partlyin section through a mechanism incorporating a third form of my invention in which the sand is subjected to a mechanical squeeze only over certain areas; and

Fig. 4 is a bottom plan view of the blow plate of Fig. 3.

In Fig. l, I have illustrated my invention as being applied to a sand blowing machine set up to form molds in flasks adapted to be stacked one upon another, and wherein an individual flask contains the upper part of one mold and the lower part of another mold. In this Fig. 1 such a flask is indicated by reference numeral and is shown as being supported on a table 12 having vertical and horizontal rollers 14 and 16 for vertically and horizontally positioning the flask.

The flask 10 is spaced above a pattern 18 aflixed to a pattern plate 20 supported on spaced bars 22 and attached by bolts 24 to a vibrator table 26. The vibrator table 26 in turn is mounted upon a table top 28 which is shown in lowered position. This table top may be raised by a cylinder 30 having a fixed piston 32 for a purpose which I shall hereinafter describe. -It will be understood that the table top 28 is ordinarily provided with a single cylinder 30, although a different number of cylinders may be utilized if desired.

Four hydraulic cylinders 34 are located above the table top and their lower ends are in sealed engagement with a plate 36which immediately overlies the table top 28. Rubber sealing means 38 may be provided to insure a seal between the cylinders and the plate 36. The cylinders 34 have heads 40, and bolts 42 attach these heads 40 and the cylinders 34 to the plate 36.

2,791,813 Patented May 7, 1957 Pistons 44 are located in the cylinders 34 and piston rods 46 support a frame 48 having an upper edge 50 adapted to engage the lower edge of the flask 10. The frame 48 is attached to the piston rods 46 by bolts 52, and spacers 54 of different thicknesses may be provided accurately to position the frame 48 relative to the piston rods 46. Spacers 56 may also be located in the cylinders 34 to limit the stroke of the pistons 44, or engaement of collars 58 and 60 may be relied upon to limit the piston strokes.

The cylinders 34 are connected to a source of hydraulic fluid under pressure through pipes 62. When the parts of the machine are in the position shown the pistons 44 p ice and frame 48 are in the raised position with the upper edge 50 of the frame 48 an appreciable distance above the upper surface of the pattern plate 20.

A second pattern 64 is located above the flask 10. This pattern 64 is attached to a pattern plate 66 which is in spaced but fixed relation to blow plate 68 forming the bottom of a sand magazine 70. It will be understood that this magazine is provided with means for blowing air from the magazine through blow tubes 72 when the parts of the machine are in the closed position.

With the parts of the machine in the position shown, fluid under pressure is admitted to cylinder 30 to raise table top 28 and bring upper edge 50 of frame 48 into engagement with flask 10. Continued upward movement of the table top 28 lifts flask 10 from its supporting rollers and moves this flask into engagement with pattern plate 66. In this position of the parts the flask 10 is firmly clamped between the upper edge of frame 48 and pattern plate 66. The flask 10 should make an air-tight seal with pattern plate 66 and with upper edge 50 of frame 48, and sealing means 74 and 76 of rubber or other suitable material may be provided to insure such an air-tight seal.

Air under pressure is now admitted to magazine 70 and this air with entrained sand flows through blow tubes 72 into fiask 10. The air escapes through an upper and lower series of vent plugs 78 and 80 which communicate with vent spaces 82 and 84 respectively. These vent plugs, however, prevent the escape of the sand which backs against the patterns 18 and 64 and completely fills the flask 10.

When the flask has been filled with sand, the air supplied to the magazine 70 is cut off and fluid is permitted to escape from the cylinders 34 by opening one or more valves controlling the pipes 62. At the same time fluid pressure is maintained on the cylinder 30, so that the table top 28 rises as fluid escapes from the cylinders 34. This upward movement of the table top 28, pattern 18 and pat tern plate 20 supported thereon causes the latter two parts to squeeze or compress the sand in the flask 1016 provide a firmer and more compact mold. This squeezing 28 and associated parts to the position shown in Fig. 1.

The flask 10 is then removed and placed on a stack of similar flasks and an empty flask rolled into active position upon the table 12, and the cycle of operations is repeated. Fluid pressure is admitted to the cylinders 34 to raise the frame or stop ring 48 relative to pattern 18 and pattern plate 20 before the cylinder 30 is again energized to raise the table top 28 in a succeeding operation. In sand blowing machines of this kind it is common to provide valvevmechanism which automaticallycontrols the operation of the machine in a predetermined and timed sequence. The valve or valves controlling the admission and discharge of hydraulic fluid to and from the cylinders can be manually controlled but areipreferably operated by the same automatic mechanism which controls the other operations of the machine.

In Fig, l the frame-or stop ring and hydraulic cylinders controlling the position of this ring' were associated with theelower" pattern and pattern plate so that the latter constituted the means for providing the mechanical sqpeeze on the sand at the completion of the blowing operation. In that form. of my invention shown in Fig. 2 this stop ring and its controlling squeeze cylinders are associated, with the. upper pattern and pattern plate. In this second embodiment 01% my invention one or more patterns 100 are attached to a lower pattern plate 102 supported? on bars104 mounted on a table top 106 having a: cylinder 108 and piston 110 whereby the table top 106 may be elevated and lowered. as heretofore described.

'Ihe flasks. 112. are placed in engagement with the rollers 114 and 116 of a fixed table 118' as in the previous embodiment.

One. or more upper patterns 120 are attached to an upper pattern plate l22 mounted in spaced but fixed relation toa. blow plate 124 forming the base of the sand magazine 126. .Aframe or stop ring 128 surrounds the upper pattern plate 122 and is attached by bolts 130 to the piston rods 132 of pistons 134 located in the hydraulic squeeze cylinders 136. These pistons are shown in; lowered: position with the lower surface of the stop ring; 128 substantially below the lower surface of the pattern plate'122.

When: fluid; under pressure is admitted to cylinder 108, table top- 106 is raised to bring strip 138 into engagement. with flask 112. Continued upward movement of the'table top 106 raises flask 112' and moves it into firm engagement with stop ring 128 which. is held against upward-.rnovementby fluid pressure in squeeze cylinders 136. In this form of my invention I have not shown rubben'seali'ng means like. the sealing means 74 and 76 oh the previous embodiment, although such sealed member: could be providedrif desired;

it Air: is: now admitted to magazine 126 to blow sand through tubes140' into flask 112.. It will be understood their the patterns 100 and*120 and the pattern plates 102 and: 1221113} be provided with any suitable arrangement of vents and vent plugs to permit escape of the air while retaining the sand; in the. flask 112. After the blowing Operation has; been completed, pressure is relieved in theisqueezez cylinders 136 while'the pressure is maintained in: the cylinders 108i to-move the table top 106, pattern 109;. pattern; plate 102, 'fla'sk 112, and stop ring 123 upwardly to subject the sand in the flask 112 to a mechanicah squeeze and. thereby compact it more firmly. Ordina1ily,,.this;squeeze will terminate when the lower surface of" the stop; ring:128' isin the same plane as the lower surfacmofi: the pattern plate 1 22. Thereafter pressure in the.6ylinder 108 is relieved and pressure in the squeeze cylinders. 136 is reinstated to return the parts to the positions shown in Fig. 2.

In: the embodiments of Figs. 1 and 2, the entire area ofYthe. sand in the flask is subjected to a mechanical squeeze following the flowing operation in which the flask is; filled; with sand. For some purposes it may be desirable to limit this mechanical squeeze to only certain areas of thesand inthe flask or other container, and in Figs: 3: and 4: I have shown a further modification of my. invention in which the sand is subjected to a mechanical :squeezeoven limited areasonly.

lmEig; 3. I have shown a core box 150'supported on the. table; top 152: of. a sand blowing machine like those heretofore described. The core box 150 has an open top: surrounded by a rim 154 shown pressed against and in: sealihgr engagement with a stop plate 156 attached to the 15$. ofi pistons: in cylinders- 160; In this figure the cylinders are diagrammatically shown, but these parts may be of a construction like those shown in the previous embodiments, or of any other suitable construction. The cylinders 160 are attached by collars 162 to a flange 164 of a sand reservoir 166 having a source of air under pressure, not shown.

Blow plate 168 forms the bottom of the sand magazine 1 and has openings 170 communicating with tubes 172.

These tubes 172.are attached to the plate 168 in any suitable manner. This blow plate is shown more fully in Fig. 4 and has secured thereto various sizes and shapes of pressure plates 174. The pressure plates are spaced below the blow plate 168 as clearly shown in Fig. 3 and 'each pressure plate surrounds one or more tubes 172.

The pressure plates 174 are attached to the blow plate 168 by screws 176, or in any other suitable manner.

The pressure plates 174 are located in openings 178 in the stop'plate 156 and are slidable in such openings. The lower faces ot the pressure plates 174 may be parallelwith the stop plate 156 or at an angle thereto, or have anyother desired shape or configuration.

When the parts are in the position shown in Fig. 3 air is admitted to the sand magazine 166 and sand andair are blown through. openings 170 and tubes 172 into core box until this core box is filled with sand. The air escapes through Vents and vent plugs (not shown) located in the stop. plate 156. These vents communicate with the vent space 180 between stop plate 156 and blow plate I68. atmosphere:

After the-core box is filled by the sand blown therein, the hydraulic pressure in cylinders "is relieved and table top 152 moved upwardly to raise core box 150 and stop plate 156- until the latter engages stops 182 on the blow plate168. This upward movement of the core box produces a mechanical squeeze on the sand in the areas below pressure plates 174. Byutilizing appropriate numbers and shapes of pressure plates and by arranging or other suitable container inserted. The cylinders 160 are again: supplied: with hydraulic fluid to hold the stop plate 156 in the lowered position shown in Fig. 3. The

parts. are now in' position for a subsequent cycle of operations.

It. isto: be understood that. my' invention is not limited to the: details. shown and: described but may assume numerous. other forms, and includes all modifications, variations and equivalents. coming: within the appended claims.

I claim:

1. Mold making apparatus of the sand-blowing type comprising a pair of pressure-members mounted for relative approaching and retracting movement and adapted to carry patterns in opposed relation thereon, meansfor supporting a flask between said members for cooperation with. such patterns; extensible stop means located between said pressure membcrs: to limit approaching movement of said. members and extensible from a positively limited squeeze position to a positively limited fill position, operatmg, means for impartingrelative approaching movement to said members to the extent determined by said stop means, means for blowing sand into a flask when such fiaslc is disposed between said members, pressure fluid operated: means for extending said step means to said extended filll position to I limit the approaching, movement of. said members to a' fill relation during filling of the flaslo and-to thereafter, upon release of. said pressure fluid operated means, allow saidsto'p means to shorten to said positively limited squeeze position wherein further From this space the air is exhausted to approaching movement of said members applied thereto by said operating means imparts a final and positively determined compacting squeeze to the sand in said flask.

2. Mold making apparatus of the sand-blowing type comprising a pair of pressure members mounted for relative approaching and retracting movement and adapted to carry patterns in opposed relation thereon, means for supporting a flask between said members for cooperation with such patterns, a frame of the same general form as said flask and disposed between said flask and one of said pressure members with said frame in alignment with said flask to constitute a continuation thereof, piston and cylinder means located on said one of said pressure members and supporting said frame thereon for engagement with said flask to limit approaching movement of said members, said piston and cylinder means having a positively limited stroke which in the extended relation of said piston and cylinder means locates said frame in a fill position with respect to said one of said pressure members and in the retracted relation of said piston and cylinder means locates said frame in a squeeze position with respect to said one of said pressure members, operating means for imparting relative approaching movement to said members to the extent determined by said piston and cylinder means, means for blowing sand into said flask, means for supplying pressure fluid to said piston and cylinder means for locating said frame in said fill position to thereby limit the approaching movement of said members to a fill relation during filling of the flask and thereafter, upon release of said pressure fluid operated means, allow said one of said pressure members to move to its squeeze position wherein further approaching movement of said members applied thereto by said operating means imparts a final and positively determined compacting squeeze to the sand in said flask.

3. Mold making apparatus of the sand-blowing type comprising first and second pressure members mounted for relative approaching and retracting movement along a predetermined path, a flask and a matched stop frame disposed in alignment between said pressure members, means for supporting a first patten plate in fixed position on said first pressure member for engagement with the adjacent edge of said flask in an approaching movement of said pressure members, means on said second pressure member for supporting a second pattern plate within said stop frame for movement within and with respect to said stop frame toward the plane of the other edge of said flask, extensible means on said second pressure member supporting said stop frame for movement relative to said second pressure member and along said path between a positively determined fill position wherein said step frame is disposed at a first predetermined distance from said second pressure member and a positively determined squeeze position in which said stop frame is disposed at a second and somewhat smaller predetermined distance from said second pressure member, means for blowing sand into said flask, operating means for imparting relative approaching movement to said pressure members to the extent determined by the position of said stop frame on and with relation to said second pressure member actuating means for extending said extensible means to locate said stop frame in said fill position with respect to said second pressure member to limit the approaching movement of said members to a first relation during filling of the flask and to thereafter, upon release of said actuating means allow said stop frame move with respect to said second pressure member to its squeeze position whereby further approaching movement of said pressure members applied thereto by said operating means imparts a final and positively limited squeeze to the sand in said flask.

References Cited in the file of this patent UNITED STATES PATENTS 377,006 Adams Jan. 31, 1888 888,004 Drysdale May 19, 1908 1,086,824 Hewlett et al. Feb. 10, 1914 1,533,221 Campbell Apr. 12, 1925 2,112,910 Jeffery Apr. 5, 1938 2,131,935 Campbell Oct. 4, 1938 2,757,424 Daniel et a1. Aug. 7, 1956 

